In recent years, while a multimedia environment has been built up, various terminals and networks have been used and as a result, user's requirements have been diversified.
For example, as performance and computing capability of terminals have been diversified, supported performance has also been diversified for each apparatus. Further, in the case of a network in which information is transmitted, a pattern, an amount, a speed, and the like of transmitted information as well as an external structure such as wired and wireless networks have been diversified for each function. A user has selected a terminal and a network to be used according to a desired function and further, spectrums of a terminal and a network which an enterprise provides to the user have been diversified.
In this regard, in recent years, as a broadcast having a high definition (HD) resolution has been extended and serviced worldwide as well as domestically, a lot of users have been familiar with high-definition and high-quality videos. As a result, organizations associated with a lot of video services have made a lot of efforts to develop next-generation video apparatuses.
Further, as the interest in ultra high definition (UHD) having four times higher resolution than an HDTV as well as the HDTV has been increased, a requirement for technology that compresses and processes higher-resolution and higher-definition videos has been further increased.
In order to compress and process the video, inter prediction technology of predicting a pixel value included in a current video from a temporally prior and/or post video, intra prediction technology of predicting another pixel value included in the current video by using pixel information in the current video, and entropy encoding technology of allocating a short sign to a symbol in which an appearance frequency is high and a long sign to a symbol in which the appearance frequency is low, and the like may be used.
As described above, when respective terminals and networks having different supported functions, and the diversified user requirements are considered, a quality, a size, a frame, and the like of a supported video need to be consequently diversified.
As such, due to heterogeneous communication networks, and terminals having various functions and various types of terminals, scalability that variously supports the quality, resolution, size, frame rate, and the like of the video becomes a primary function of a video format.
Accordingly, it is necessary to provide a scalability function so as to achieve video encoding and decoding in terms of time, space, video quality, and the like in order to provide a service required by the user under various environments based on a high-efficiency method for video encoding.